Interior module installation in an aircraft fuselage

ABSTRACT

A method of installing interior modules to support structures in an aircraft fuselage comprises attaching fixed ends of a plurality of tie rods to the support structures; and determining installation length of the tie rods, installation spacing between free ends of the tie rods, and installation orientation of the tie rods prior to positioning the interior module for installation. The method further comprises securing tie rod holding fixtures to the tie rods to hold the spacing and orientation at or near final configuration to facilitate installation of the interior modules.

BACKGROUND

During a typical installation of overhead stowage bins in the fuselageof a large commercial aircraft, a first shop enters the fuselage,installs tie rods to exposed frames and other support structures of thefuselage, and then leaves the fuselage. Later, a second shop enters thefuselage with the overhead stowage bins, and secures the overheadstowage bins to the tie rods.

It is undesirable for the tie rods to hang freely after installation.Stress is placed on fixed ends of the tie rods. To reduce the stress,free ends of the tie rods may be secured to the support structures viazip ties.

When the second shop installs an overhead stowage bin, the zip ties arecut to let the tie rods hang, the bin is lifted into position, a beamtool is used to set length, orientation and spacing of the tie rods, andthen the overhead stowage bin is secured to the free ends of the tierods. This procedure is performed for each overhead stowage bin. In alarge commercial aircraft, this procedure is repeated many times.

SUMMARY

According to an embodiment herein, a method of installing interiormodules to support structures in an aircraft fuselage comprisesattaching fixed ends of a plurality of tie rods to the supportstructures; and determining installation length of the tie rods,installation spacing between free ends of the tie rods, and installationorientation of the tie rods prior to positioning the interior modulesfor installation. The method further comprises securing tie rod holdingfixtures to the tie rods to hold the spacing and orientation at or nearfinal configuration to facilitate installation of the interior modules.

According to another embodiment herein, an aircraft fuselage comprises aplurality of support structures; a plurality of tie rods having fixedends secured to the support structures; and a plurality of tie rodholding fixtures. Each fixture is clamped to a set of tie rods to hold apredetermined spacing and orientation of free ends of the tie rods.

According to another embodiment herein, a tie rod holding fixture for aset of tie rods comprises a collapsible fixture body, and first andsecond clasps at respective ends of the fixture body. The first andsecond clasps are configured to grasp first and second vertical tie rodsof the set. The tie rod holding fixture further comprises a third claspcoupled to the fixture body and configured to grasp a lateral tie rod ofthe set.

These features and functions may be achieved independently in variousembodiments or may be combined in other embodiments. Further details ofthe embodiments can be seen with reference to the following descriptionand drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of an aircraft fuselage including a pluralityof interior modules and a support system for supporting the interiormodules.

FIG. 2 is an illustration of an example an interior module and tie rods.

FIG. 3 is an illustration of tie rods secured to a support structure ofthe aircraft fuselage.

FIG. 4 is an illustration of tie rods secured to an overhead stowagebin.

FIG. 5 is an illustration of another example an interior module and tierods.

FIG. 6 is an illustration of a method of securing interior modules tosupport structures of an aircraft fuselage.

FIG. 7 is an illustration of equipment for securing interior modules tosupport structures of an aircraft fuselage.

FIG. 8A is an illustration of a tie rod holding fixture that is holdinga lateral tie rod and two vertical tie rods prior to installation of aninterior module.

FIG. 8B is an illustration of the tie rod holding fixture and the tierods during installation of an interior module.

FIGS. 9A and 9B are illustrations of a first example of a tie rodholding fixture.

FIGS. 10A and 10B are illustrations of a second example of a tie rodholding fixture.

DETAILED DESCRIPTION

FIG. 1 illustrates an aircraft fuselage 110 including a plurality ofsupport structures 120. The support structures 120 include primarysupport structures and secondary support structures. Examples of theprimary support structures include, but are not limited to, airframemembers (e.g., frames and stringers), and floor beams. Examples of thesecondary support structures include, but are not limited to, rails andladders.

The fuselage 110 further includes a plurality of interior modules 130.The interior modules 130 include, but are not limited to, overhead bins,ladders, electrical racks, and monuments (e.g. lavatories. galleys,partitions, closets, and other large floor-mounted items).

Some interior modules 130 may be suspended from secondary supportstructures (e.g., rails) that, in turn, are suspended from primarysupport structures (e.g. a frame). Other interior modules 130 may besuspended directly from primary support structures. Still other interiormodules 130 may be suspended from secondary support structures that aresuspended from other secondary support structures.

The fuselage 110 further includes tie rods 140 for suspending theinterior modules 130 from the support structures 120. The tie rods 140have adjustable length for precise positioning of the interior modules130.

For the purposes herein, a tie rod 140 is defined as an elongated bodyhaving adjustable length. For instance, a tie rod 140 may include anelongated tube having threaded ends. Each threaded end may include athreaded bearing that is turned into an out of the tube to adjustlength. Each threaded end may be rotated independently by hand or atool. After the length of a tie rod 140 has been adjusted, a jam nut maybe tightened to fix its length. Thus, the tie rods 140 include withoutlimitation conventional tie rods, conventional turnbuckles, andconventional struts. A conventional tie rod has the same type ofthreaded ends (e.g., both right-hand threads), whereas a conventionalturnbuckle has threaded ends of different types (right-hand threads atone end and left-hand threads at the other end).

An end of the tie rod 140 that is or will be fixed to a supportstructure 120 is referred to as a “fixed” end. An end of the tie rod 140that is or will be secured to an interior module 130 is referred to as a“free” end.

FIG. 2 illustrates an example of an interior module 130 that is attachedto a primary support structure via tie rods 140. The interior module 130of FIG. 2 includes an overhead stowage bin 210. The tie rods 140 includevertical tie rods 220 and lateral tie rods 230. Free ends of the tierods 220 and 230 are secured to center rails 240 on the overhead stowagebin 210.

FIG. 3 illustrates how the vertical and lateral tie rods 220 and 230 maybe secured to a support structure 120 (e.g., a crown structure). Fixedends of the tie rods 220 and 230 are attached (e.g., with a bolt orquick disconnect pin) to clevises 310 and 320, which are fastened to thesupport structure 120. Compare the relative orientations of the devises310 and 320. The clevis 310 for the vertical tie rod 220 is relativelynormal to the support structure 120, whereas the clevis 320 for thelateral tie rod 230 is angled.

FIG. 4 illustrates how the vertical and lateral tie rods 220 and 230 maybe secured to the overhead stowage bin 210. The vertical tie rods 220hang from the support structures 120 at no more than a slight angle(e.g., 15 degrees from vertical), and the lateral tie rods 230 areangled at about 45 degrees from vertical. Free ends of the vertical andlateral tie rods 220 and 230 terminate in devises 410 and 420, which aresecured to a fitting 430. The fitting 430 engages one of the centerrails 240. Other tie rods may be secured to the overhead stowage bin 210in a similar manner, or they may be secured directly to the overheadstowage bin 210.

FIG. 5 illustrates another example of an interior module 130 and its tierods 140. The interior module 130 of FIG. 5 includes a ladder 510. Thetie rods 140 include vertical tie rods 520 and lateral tie rods 530.Free ends of vertical tie rods 520 are secured to center rails 540 ofthe ladder 510. Free ends of lateral tie rods 530 are secured to crossbars 550 of the ladder 510.

Reference is now made to FIGS. 6 and 7, which illustrate a method andequipment for securing interior modules 130 to support structures 120 ofthe fuselage 110 of an advanced commercial jetliner. The method may beperformed while the fuselage 110 is progressing through a movingassembly line. The moving line assembly refers to a build process frominitial buildup of fuselage sections to roll out at final assembly.During this build process, fuselage body sections may be supported andmoved by crawlers in a straight line, while various types of work areperformed on the fuselage sections. Subsequently, the fuselage sectionsare joined together to form a full fuselage 110.

As used herein, work performed on the fuselage 110 refers to work thatis performed on one or more sections of the fuselage 110 or work that isperformed on a full fuselage 110.

The various type of work on the fuselage 110 is divided among “shops.” Ashop may be a work team such as a group of mechanics. Each shop has itsown responsibility.

Prior to the method of FIG. 6 being performed, a shop has alreadyentered the fuselage 110 and attached devises to the support structures120. Thereafter, the interior of the fuselage 110 may be wrapped withinsulation. Even if the interior of the fuselage 110 has been wrappedwith insulation, the clevises will still stick out of the insulation andwill be visible.

The method of FIG. 6 begins after the clevises have been attached to thesupport structures 120. At block 610, a first Systems and Installation(S&I) shop enters the fuselage with tie rods 140, fasteners, andequipment including an interior work stand 710, a beam tool 720, and tierod holding fixtures 730.

At block 620, the work stand 710 is moved into position. The work stand710 may be a single elevated platform that spans the entire interiorlength of the fuselage 110.

At block 620, at each interior module location, the fixed ends of aplurality of tie rods 140 are secured to one or more support structures120. Not all exposed clevises fitting are necessarily used. The firstshop may use drawings to determine which clevises and tie rods 140 touse.

At block 630, a beam tool 720 is used to determine installation lengthof the tie rods 140, installation spacing between free ends of the tierods 140, and installation orientation of the tie rods 140. The beamtool 720 may include an elongated beam 722 having stations 724. Thestations 724 correspond to locations of attachment points on theinterior modules 130. The beam tool 720 may be indexed to two outboardrails. Three-point locations (WL, BL and STA) of the free ends may bepre-set on the beam tool 720. Length of each tie rod 140 may be adjustedso that its free end touches a point 725 on a station 724.

At block 640, the tie rod holding fixtures 730 are secured to the tierods 140. The tie rod holding fixtures 730 hold the spacing andorientation of the free ends of the tie rods 140. Their purpose is tohold the tie rods 140 at or near final configuration to facilitateinstallation of the interior modules 130. Tie rod holding fixtures 730may be applied to most, if not all, of the tie rods 140.

FIG. 8A illustrates an example of a tie rod holding fixture 730 at thisstage of work. The tie rod holding fixture 730 is holding a lateral tierod 230 and two vertical tie rods 220. The tie rods 220 and 230 haveclevises at their free ends. These devises will eventually be secured toan interior module 130.

At block 650, the first shop completes its work, removes the work stand710 and the beam tool 720, and leaves the fuselage 110. Other fuselageassembly tasks may be performed. Several days may elapse before thefuselage 110 is ready for the interior modules 130 to be installed.

At block 660, a second S&I shop enters the fuselage 110 with interiormodules 130 and equipment for installing the interior modules 130. Theinstallation equipment may include lifts for raising the interiormodules 130 to their installation positions, and step ladders forenabling installers to attach the free ends of the tie rods 140 to thefittings on the interior modules 130. The work stand 710 and beam tool720 are not needed by the second shop.

At block 670, the interior modules 130 are installed. Duringinstallation, an interior module 130 is lifted into an approximateposition for installation, and each tie rod 140 is unclipped from thetie rod holding fixture 730, and secured to the interior module 130. Thesame installation procedure may be performed for each interior module130.

FIG. 8B illustrates an example of an interior module 130 after beinglifted into an approximate position for installation. The interiormodule 130 is supported by center rails 810. Clevises 820 and 830 at thefree ends of the tie rods 220 and 230 are at or proximate their fittingson the interior module 130 and center rails 810 (the free ends may beslightly wider to make the installation easier). The tie rod holdingfixture 730 holds the orientation and spacing of the free ends.

Each tie rod 220 and 230 is removed from the tie rod holding fixture730, and its clevis 820 or 830 is placed over a fitting. Each clevis 820and 830 is secured to its fitting by means such as a bolt or quickconnect pin. The installed interior module 130 is illustrated in FIG. 2.

Only one tie rod holding fixture 730 is illustrated in FIGS. 8A and 8B.A second tie rod holding fixture 730 may be used to hold tie rods 140 atan opposite side of the interior module 130. A third tie rod holdingfixture 730 may be used to hold any tie rods between the first andsecond sides of the interior module 130.

Reference is once again made to FIG. 6. At block 680, after the interiormodules 130 have been installed, the second shop leaves the fuselage110.

The use of the tie rod holding fixtures 730 eliminates the need for thefirst shop to secure free ends of the tie rods 140 to support structures120 via zip ties, and it eliminates the need for the second shop to cutthe zip ties to release the free ends of the tie rods 140. The use ofthe tie rod holding fixtures 730 also eliminates potential foreignobject debris (the cut zip ties) during installation.

The tie rod holding fixtures 730 also enable the workflow of interiormodule installation to be changed. It enables the beam tool 720 to beused earlier in the workflow to adjust the length of the tie rods 140.

The method of FIG. 6 is also safer and more ergonomic than conventionalmethods, in that it enables the beam tool 720 to be used whileinstallers are standing on the work stand 710 instead of ladders. Thework stand 710 is inherently more stable than individual step ladders.

The method of FIG. 6 is not limited to advanced commercial jetliners. Itmay be applied to other types of aircraft, such as military aircraft andcargo aircraft.

The tie rod holding fixture 730 is not limited to any particularconfiguration. A first example of the tie rod holding fixture 730 isillustrated in FIGS. 9A and 9B, and a second example is illustrated inFIGS. 10A and 10B.

In both examples, the tie rod holding fixture 730 is collapsible betweena stowed position and a deployed position. Collapsing the tie rodholding fixture 730 makes it easier to handle.

In the example of FIGS. 9A and 9B, the tie rod holding fixture 730includes an elongated fixture body 910 having an adjustable length. Thefixture body 910 includes first and second segments 920 and 930, and ahinge 940 for hinging a near end of the first segment 920 to a near endof the second segment 930. First and second arms 950 and 960 extend fromfar ends of the first and second segments 920 and 930.

The tie rod holding fixture 730 further includes first, second and thirdclasps 970, 980 and 990. The first and second clasps 970 and 980 aresecured to the first and second telescoping arms 950 and 960, and thethird clasp 990 is secured to the hinge 940. The clasps 970, 980 and 990may be similar to conventional snap clamps that are used for grabbingand locating pipes.

FIG. 9A shows the tie rod holding fixture 730 in the deployed position.The first and second segments 920 and 930 are aligned. The first andsecond arms 950 and 960 can be slid into and out of their correspondingsegments 920 and 930 to adjust distance between the first and secondclasps 970 and 980.

The first and second clasps 970 and 980 firmly grasp the vertical tierods 220. The third clasp 990 firmly grasps the lateral tie rod 230. Bysupporting the lateral tie rod 230, the third clasp 990 reduces stresson the clevis holding the fixed end of the lateral tie rod 230 to thesupport structure 120.

FIG. 9B shows the tie rod holding fixture 730 after it has beencollapsed to the stowed position. The first and second segments 920 and930 are side by side, and the first and second clasps 970 and 980 areside by side.

In the second example of FIGS. 10A and 10B, the tie rod holding fixture730 includes fixture body 1000. The fixture body 1000 includes aconnector 1010 and first, second and third arms 1020, 1030 and 1040.Each arm 1020, 1030 and 1040 can be inserted into and removed from acorresponding receptacle in the connector 1010. The fixture body 1000further includes tube portions 1050 that can be slide into and out ofthe arms 1020, 1030 and 1040. First and second clasps 1070 and 1080 aresecured to the tube portions 1050 at the ends of the first and secondarms 1020 and 1030. A third clasp 1090 is secured to the tube portion1050 at the end of the third arm 1040.

FIG. 10 A shows the tie rod holding fixture in a deployed position. Eacharm 1020, 1030 and 1040 is inserted in a receptacle in the connector1010, whereby the tie rod holding fixture 730 has a T-shape. The firstand second arms 1020 and 1030 are axially aligned, and the third arm1040 is orthogonal to the first and second arms 1020 and 1030. The tubeportions 1050 may slide in and out of their corresponding arms 1020,1030 and 1040 to adjust the positions of the clasp 1070, 1080 and 1090.

As illustrated in FIG. 10B, the tie rod holding fixture 730 may becollapsed by removing the arms 1020, 1030 and 1040 from the connector1010. The arms 1020, 1030 and 1040 may be tethered to the connector 1010by chords 1060. The arms 1020, 1030 and 1040 may be arranged side byside in a compact position for stowage.

1. A method of installing interior modules to support structures in anaircraft fuselage, the method comprising: attaching fixed ends of aplurality of tie rods to the support structures; determininginstallation length of the tie rods, installation spacing between freeends of the tie rods, and installation orientation of the tie rods priorto positioning the interior modules for installation; and securing tierod holding fixtures to the tie rods to hold the spacing and orientationat or near final configuration to facilitate installation of theinterior modules.
 2. The method of claim 1, further comprisinginstalling the interior module to the free ends of the tie rods whileremoving the tie rod holding fixture.
 3. The method of claim 2, whereinthe interior module includes an overhead stowage bin.
 4. The method ofclaim 2, wherein the attaching, determining and securing are performedwhile the fuselage is progressing through a moving assembly line.
 5. Themethod of claim 4, wherein a plurality of shops perform work on thefuselage while the fuselage is progressing through the moving assemblyline, wherein a first shop of the plurality secures the holding fixturesto the tie rods, and later, a second shop of the plurality installs theinterior modules to the free ends of the tie rods.
 6. The method ofclaim 5, wherein the first shop attaches the fixed end of the tie rodsto exposed clevises attached to the support structures.
 7. The method ofclaim 5, wherein the first shop uses a beam tool to determine theinstallation length and orientation of the tie rods and the installationspacing between the free ends of the tie rods prior to securing the tierod holding fixtures.
 8. The method of claim 7, wherein the first shopalso uses an elevated platform that spans an interior length of thefuselage to secure the tie rod holding fixtures to the tie rods.
 9. Themethod of claim 7, wherein the second shop installs the interior moduleswithout using the beam tool.
 10. The method of claim 1, wherein the tierods include first and second vertical tie rods and a lateral tie rod;and wherein each tie rod holding fixture holds the first and secondvertical tie rods and the lateral tie rod.
 11. The method of claim 10,wherein at least one of the tie rod holding fixtures includes anelongated fixture body having an adjustable length, first and secondclasps located at opposite ends of the fixture body, the first andsecond clasps configured to firmly grasp the vertical tie rods, and athird clasp coupled to the fixture body and configured to firmly graspthe lateral tie rod.
 12. The method of claim 11, wherein the fixturebody is collapsible between a stowed position and a deployed position;and wherein the fixture body is moved from the stowed position to thedeployed position just prior to securing the tie rod holding fixtures tothe tie rods.
 13. The method of claim 12, wherein the fixture bodyincludes first and second segments having respective near ends hingedtogether by a hinge; wherein the third clasp is secured to the hinge;and wherein the first and second segments are side by side and the firstand second clasps are side by side when the fixture body is in thestowed position.
 14. The method of claim 12, wherein the fixture bodyincludes a connector and first, second and third elongated arms; whereinthe first, second and third clasps are at far ends of the first, secondand third arms; and wherein the fixture body is in the deployed positionwhen near ends of the first, second and third arms are inserted in theconnector.
 15. The method of claim 14, wherein the first, second andthird arms are tethered to the connector by cords.
 16. An aircraftfuselage comprising: a plurality of support structures; a plurality oftie rods having fixed ends secured to the support structures; and aplurality of tie rod holding fixtures, each fixture clamped to a set oftie rods to hold a predetermined spacing and orientation of free ends ofthe tie rods.
 17. The aircraft fuselage of claim 16, further comprisinga plurality of interior modules inside the fuselage, wherein theinterior modules are not attached to the free ends.
 18. A tie rodholding fixture for a set of tie rods, the fixture comprising: acollapsible fixture body; first and second clasps at respective ends ofthe fixture body, the first and second clasps configured to grasp firstand second vertical tie rods of the set. a third clasp coupled to thefixture body and configured to grasp a lateral tie rod of the set. 19.The fixture of claim 18, wherein the fixture body includes first andsecond segments, and a hinge connected between respective near ends ofthe first and second segments; wherein the third clasp is secured to thehinge.
 20. The fixture of claim 18, wherein the fixture body includes aconnector and first, second and third elongated arms; wherein the first,second and third clasps are at far ends of the first, second and thirdarms; and wherein the fixture body is in a deployed position when nearends of the first, second and third arms are inserted in the connectorsuch that the first and second arms are axially aligned, and the thirdarm is orthogonal to the first and second arms.